Rabbit Hemorrhagic Disease Virus (RHDV2)
The RHDV2 virus
Rabbit Hemorrhagic Disease Virus (or RHDV2) is a species-specific Calicivirus, meaning it affects rabbits but won’t infect other mammals. It’s hardy in the environment and can spread easily and quickly.
The virus is transferred by excretions of infected rabbits, including the remains of a rabbit that have passed. Even a recovered rabbit may be contagious for an additional 30-100 days.
The virus is spread by direct contact and by fomites (objects carrying the virus); this includes flies or other insects and scavenging animals in the wild. Unfortunately, it also applies to food (hay, vegetables) and clothing.
Please note that RHDV2 is in no way related to the current COVID-19 virus.
Protecting your rabbits from RHDV2
Active virus particles have been found on rabbit remains 3 months later—even in natural environment conditions and the virus can withstand temperatures up to 122 °F (50 °C) for 1 hour.
A 1% bleach solution, or a cleaning product like Rescue, kills the virus on surfaces. If you use bleach, remove your rabbit from the vicinity while you are cleaning. Dry all surfaces completely before letting your rabbit return to that space.
Other than having your rabbit vaccinated, you should practice strict biosecurity measures to prevent exposure:
- Wash your hands thoroughly before handling your rabbits.
- Consider changing clothes and washing them if you were recently outdoors or if you work with other animals.
- Take shoes off before entering your home.
- Do not bring any outdoor objects inside; this includes foraged plants, grass, tree branches, etc.
- If you see any deceased wild rabbits, contact your local or state wildlife authority—do not touch the remains!
- Keep rabbits indoors and avoid play dates with animals from outside your home during this time.
- Do not bring new rabbits into your home. If you must, quarantine new rabbits in a separate room with separate food, toys, and bedding. Care for quarantined rabbits after any others in the home. This quarantine should be in place for at least 14 days, but that does not guarantee the quarantined rabbit is not an asymptomatic carrier shedding the virus.
- Use window and door screens to prevent flies and other insects from coming indoors. Apply regular flea control to rabbits, cats, and dogs in the home. Please note that FRONTLINE should not be applied to rabbits.
- Know where your hay and vegetables come from. Hay on the shelf now is typically harvested the previous season, so it should be safe. Oxbow hay, for example, harvested its hay in 2019, before any cases were reported in the southeastern U.S. Read more about how Oxbow is protecting your rabbits on their blog.
Of course, discuss any concerns with your usual rabbit-savvy veterinarian, and plan to vaccinate your rabbits, especially if you live in or near confirmed outbreak areas.
The incubation period, the time between exposure and illness, is 1-3 days. A variety of symptoms often develop rapidly and without warning and the mortality rate for this disease can be high in naive populations. There is no cure. Supportive care can be given but may not be successful.
Prevention is key—so please vaccinate as soon as you can and follow the biosecurity measures we covered earlier. If you suspect your rabbit has been exposed or suddenly becomes sick, please seek veterinary care ASAP.
RHDV is not a new virus, but it is new to Texas; RHDV1 was first discovered in China in 1984. RHDV2 was first identified in France in 2010.
As of May 17, 2020, Lampasas County (about 75 miles northwest of Austin) recorded the closest confirmed case to Houston. RHDV2 has not been confirmed in the greater Houston area. The only reported case in 2021 thus far was in Tom Green County (near San Angelo) on March 5. If your vet suspects an RHDV case, they should contact the state veterinarian.
RHDV2 is regularly found in Europe, which is why they already have the vaccine. In the U.S., it is considered a Foreign Animal Disease and importing of the vaccine was illegal prior to this outbreak and subsequent confirmation of reported cases.
It was previously believed that RHDV2 did not affect wild rabbits, but cases in wild populations have been confirmed in Texas. So we’re still learning about this virus and its effects.
Texas vets received special permission to import specific types of the RHDV2 vaccine, and several greater Houston-area clinics are taking appointments now.
The RHDV2 vaccine
Vaccination is recommended for healthy rabbits over 10 weeks of age. The vaccine is safe for pregnant does, but babies will still require their own dose when they are of age. The vaccine will take a minimum of 7 days to provide protection. You will need to vaccinate annually if this disease becomes endemic in Texas.
Reactions to the vaccine are rare. This is a “killed” (meaning non-active) vaccine; a rabbit can not contract RHDV2 from the vaccine.
The vaccine must be administered by a veterinarian with a current relationship with a rabbit and owner, so exams and associated fees are required. Owners must sign a waiver acknowledging that this vaccine is imported and not produced or previously approved in the U.S.
Only pet rabbits can be vaccinated and these rabbits cannot be released into the wild; legally, we also have to inform you that rabbits cannot be consumed within 21 days of vaccination. All rabbits will be given a vaccine certificate (similar to Rabies).
It is important to note that the vaccine is not a guarantee of protection; it helps rabbits survive exposure to the disease which would otherwise be certainly fatal.
Also, because of how the vaccine is made, some people may not want to use it due to the ethics of its development. We cannot make the decision to vaccinate for you. We can say that we plan to vaccinate all rabbits in our foster care. Please do your own research and learn as much as you can about the virus and vaccine so you can make the best decision for your rabbit(s).
Vaccination in the Houston area
To get your rabbit(s) vaccinated, contact Gulf Coast Veterinary Specialists (GCVS) or Animal Medical Center of the Village (AMCV) in Houston, ABC Animal & Bird Clinic in Sugar Land, or Cypress Lakes Animal Hospital to make an appointment.